Relay



Feb. 12, 1946.

M. FIEHL RELAY Filed May 5, 1944 INVENTOR -M/CHA 1. F//-/L ATTORNEY Patented Feb. 12, 1946 UNITED STATES PATENT OFFICE RELAY Michael Fiehl, Endicott, N. Y., assignor toilnternational Business Machines Corporation, New York, N. Y., acorporation of New York Application May 5, 1944, Seriaililo. 534,235 1 Claim. (01. 175-436) Thisinvention relates to electromagnetic relays and has for its principal object the improvement thereof for the prevention of vibration or bounce" of the armature of the relay.

In carrying out the object of the invention, an inertia element in the form of a weight is suspended from the relay armature in such manner that the element is free to move relatively to the armature, particularly in the direction of movement of the armature. As a result, when the armature upon attraction or release strikes the usual limit stops from which it has a'normal tendency to rebound, the inertia of the element applies a counterforce opposite in direction to the direction of rebound and thereby serves to prevent or limit the extent of such rebound. This limiting action is especially important where the armature controls the opening and closing of contacts as it prevents communication of undesirable rebound to such contacts.

Other objects of the invention will be pointed out in the following description and claim and illustrated in the accompanying drawing, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawing:

Fig. 1 is a side elevation of a well known form of electromagnetic relay showing the manner in which the invention is applied thereto.

Fig. 2 is a sectional view taken on lines 2-2 of Fig. 1.

The relay shown in the drawing is of the type shown and described in the patent to Lake & Pfaff No. 2,282,066 granted May 5, 1942, and comprises a U-shaped frame l1 within which is mounted the yoke 20 supporting the magnet winding 22. Screws 23 serve to hold the yoke in position in frame i1. Bracket 24 supports the armature pivot pin 25 and armature 21 is hooked at its upper end and provided with a leaf spring 28 to furnish connection with pin 26.

Embedded in frame l1 are current conducting contactors or stops 3|, 32, 33 and 34, of which 34 is connected by a wire to the winding 22. A wire contact spring 85 is threaded through an opening 36 in an adjustable plate 31, through an opening 38 in contactor 3| and between the ends of contactors 32 and 33'. Piate'31is adjusted to the 7 right so that the right edge of opening 38 serves as a fulcrum about which the lower end of wire 35 is constantly ur ed toward the left into ento armature 21 and has an opening 41 through which wire 35 passes. When magnet 22 is energized, armature 21 is rocked counterclockwise against edge 29 of yoke and in doing so wire is engaged by the left edge of opening 41 in bracket and flexed to disengage contactor 32 and engage contactor 33. This breaks the electrical connection between 3| and 32 and makes a connection between 3| and 33. Armature 21 is made of copper and chromium plate to overcome residual magnetism.

Upon deenergization of magnet 22, wire 35 which is under tension swings the parts back to the normal position shown, and in so doing the lower end 21a of armature 21 strikes an adjacent edge of frame l1. In the prior construction of this type of relay, as exemplified in the patent referred to, a damping spring was provided which coacted with the lower edge of armature 21 to limit the rebound of the armature, but this, it has been found, imposes an undesirable frictional load on the armature.

In accordance with, the present invention, such damping spring (designated 30 in the patent) is removed and a plate 62 having depending fingers 62a and 62b is secured to the bracket 40 and arof the spring are placed circular weights 5| whose outer diameter is less than the inner diameter of the spring;

gagement with stop 32 to close a circuit connecv tion between II and 32. v

A bracket l0 of insulating material is riveted These weights constitute inertia elements and their action is such that, when the armature 21 is rocked suddenly in either direction, the weights through spring will be suddenly urged in the same direction and thus move with the armature. Upon subsequent stopping of the armature, the Weights due to their inertia will continue in the initial direction and strike the side of spring 50, setting up a force counter to the force and direction of the rebound oi the armature.

The weights 5| striking the sides of spring 50 set up a vibration in the spring whose frequently also aids in dissipating the energy. When armature 21 is attracted by magnet 22, the force of attraction is usually great enough to prevent rebound so that the action of weights 6| is not as important as when the armature is released. In the latter case, the rebound of armature end 21a ,if undamped, would cause wire 35 to "flutter" and result in a poor contacting engagement with contactor 22. With the employment 0! weights H and spring 60, this flutter is eliminated and upon restoration of armature 21, wire 35 engages contactor 32 and remains in engagement to furnish a continuous electrical connection therethrough.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a single modification, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore to be limited only as indicated by the scope of the following claims.

What is claimed is:

In a relay, the combination of a magnet and an armature, a spring for withdrawing the armature from the magnet, a stop for limiting the extent of withdrawal, a coil spring extending transversely to the direction of movement of the armature with the ends of the spring secured to the armature, a weight freely movable within the coils of the spring, the inertia of said weight acting when the movement of the armature is interrupted to limit the rebound of the armature.

MICHAEL FIEHL. 

